1. Field of the Invention
The present invention relates to a vehicle disc brake for use on vehicles such as motor vehicles and motorcycles and more particularly to a construction of a pad retainer for movably supporting lug pieces of a shoe of a friction pad by pad guide grooves on caliper supporting arms.
2. Description of the Related Art
In a disc brake in which lug pieces which are provided at both side portions of a shoe of a friction pad so as to project therefrom are movably supported in pad guide grooves which are formed so as to face each other in a pair of caliper supporting arms, so that the friction pad is supported movably in a disc axis direction, in general, a pad retainer which is formed of a thin metallic plate is interposed between the pad guide groove and the lug piece. Some of such pad retainers include an inner piece which is brought into abutment with a surface of the pad guide groove which lies inwards in a disc radial direction and a pad returning portion which is formed so as to connect to the inner piece not only for biasing a lug piece of the friction pad outwards in the disc radial direction but also for biasing the lug piece in a direction in which the lug piece moves away from the disc rotor. This pad returning portion is formed by forming an elastic loop portion by bending a proximal portion of a narrow elongated piece, which is provided to extend from a side of the inner piece which lies further from the disc rotor, from the outside in the disc radial direction in a direction in which the narrow elongated piece extends towards the disc rotor so as to be formed into an arc-like shape and inclining a distal end portion of the narrow elongated piece which extends from the elastic loop portion towards the disc rotor outwards in the disc radial direction. Then, even in the event that the lug piece of the friction pad is pressed in a dislodgement direction in which the lug piece moves away from the disc rotor when the friction pad is temporarily assembled to the caliper supporting arms, the elastic loop portion is brought into abutment with a side of the lug piece which lies further from the disc rotor, whereby the dislodgement of the friction pad from a caliper bracket is prevented (refer to Japanese Patent No. 3934063, for example).
In the disc brake referred to above, however, since the elastic loop portion is provided at the side of the pad guide groove which lies further from the disc rotor and so as to project outwards in the disc radial direction, when the friction pad is assembled, the friction pad has to be assembled so that the lug piece does not interfere with the elastic loop portion, whereby the assembling properties of the friction pad is deteriorated.